A series of fires whipped by powerful winds incinerated parts of Northern California's wine country early this week. The eight-county blaze has been called one of the deadliest firestorms in state history.

Nearly two dozen fires erupted late Sunday night in the wine-making region north of San Francisco. Tens of thousands of people have fled, and at least 3,500 homes, businesses, and other structures have burned.

A blaze called the Tubbs Fire has burned at least 34,000 acres in and around the city of Santa Rosa, according to the Cal Fire website. The Atlas Fire in Napa Valley has devastated an additional 43,000 acres. The extent of the damage is unknown.

This map shows the counties affected by the firestorm and where some of the fires are burning, as of 5 PM ET (2 PM PT) on Thursday. Scroll over the map to see county names.